Flat Gate Small Opening Study Of Flow Coefficient And The Gate After The Numerical Simulation Of Flow Analysis

With the "second five"national give importance in water conservancy and the vigorous development of water conservancy and hydropower construction giant, many water conservancy and hydropower projects under construction and more proposed to head high, the flow characteristics significantly. In the high head, high flow, providing a small flow to the downstream of life, industrial or irrigation water problem has become particularly prominent. This presented a high head chamber of the gate opening to run a small problem.High head and general head is very different, quantitative qualitative changes caused, this is one of the basic law of dialectics. We follow the conventional design method,principle, as a means to design a 50m high dam, assuming the discharge to safe operation of the tunnel, hence increasing the height to the height of 200m, the discharge may not be able to tunnel to ensure safe operation. Therefore, a small high-head gate after gate opening flow characteristics are worthy of further study. In practice project, the form of the gate discharge structure in used by the main gate and radial gate flat. Gates which have a long section before the tunnel of pressure flow pattern is different from the gates which have a short segment in front of the tunnel of pressure flow pattern, so in calculating the discharge capacity of discharge tunnel can not be confused with the gate discharge coefficient formula. In addition, high head plate gate, when the gate opening is less than 30%, discharging a small flow, the flow is affected by the gate slots and the vertical shrinkage of the former gate, gate after the flow pattern becomes more complex, environment for the formation of jet atmospheric wall jet, flow velocity high, the water forms a parabola-shaped tongue. Gate current flow pattern after the study did not consider the impact of gate slot. Gate at present flow pattern after the study did not consider the impact of gate slot. Therefore, the existing formula with high head and a small gate opening when the Discharge Volume the larger difference between the actual results, so for such a small opening high head situation in the gate discharged water tunnel study of flow characteristics in both theoretical and practical importance Significance.Based on test data and related data analysis, presented in front of gate gate after a long segment of pressure flow freely out of the gate plate discharge coefficient is calculated, and the flat gate after gate along the tongue of water hydraulic elements of the analysis, Based on the derived length of a pressure front gate gate section after the gate free outflow of the gate flat water depth and its location after the contraction formula Finally, the tongue plate gate gate water feature points after the formula.Discharge tunnel for more than head high gate and radial gate by plate combination in the form of control the size of Discharge. This paper studies used discharge tunnel sluice gate in the form of plates. The main contents are:flow characteristics at the gate (this study is the flow coefficient), after the free-flow tunnel gate flow characteristics in paragraph (this article is the main gate of no pressure section of the flow pattern), refers to the flow characteristics tunnel gate in the case of high head and a small opening when the flow pattern. At present, many domestic research projects targeting the actual high-head gate flow characteristics of the small opening and applied research in engineering practice, but the lack of systematic basic research and the results of its hydraulic characteristics of studies, especially after the water gate flow and distribution of turbulent energy distribution and the turbulent dissipation rate and other aspects of the distribution is almost blank.Southwest region in 2010 severe drought, the majority of provinces and autonomous regions suffered from floods and mudslides some local sudden severe flash floods once again warning us to accelerate the water conservancy construction delay. With the rapid development of science and technology, modem hydraulics has changed a lot. Theoretical analysis, experimental investigation and numerical simulation has become of the three basic means of hydraulics. With advances in computer technology, computational fluid dynamics in hydraulic engineering to obtain a wide range of applications, and achieved good results, and has been recognized by the engineering sector. This is the Yunnan Natural Science Foundation (2006E0018M) "high head chamber of the gate opening flow characteristics of the small" experimental research based on the high head and a small gate opening discharge coefficient calculated a theoretical analysis, the influence of small opening high head gates of the main parameters of the flow coefficient was studied. Mechanical test methods and then take the water, by changing the gate opening, gate before the head and other conditions of no pressure on the brake hydraulic characteristics of flow observation segment. Finally, a numerical simulation method to study the changes in these two factors alone after the flow pattern on the gate of. Finally, use the numerical simulation method to study the influence of change in these two factors alone after the flow pattern on the gate and the theoretical analysis results, test results and numerical simulation results for mutual authentication.